Glass lens



' UNITED STATES HENRY M. PAINE, OF NORT OXFORD, MASSACHUSETTS.

EATENT onirica.

GLASS LENS.

Specification of Letters Patent No. 4,786, dated October 3, 1846.

.To all whom 2f may concern.'

Be it known that I, HENRY M. PAINE, of North Oxford, in the county of )Vorcester and State of Massachusetts, have invented a` the following is a full, clear, and exact de- 4 script-ion of the construct-ion and operation of the same, reference being had to the vannexed drawings, making a part of this speciication, in which- Figure 1, is a perspective view of the fusing furnace. Fig. 2, a transverse open view of the furnace, as if cut down through the center, lshowing the interior of the fusing oven-the fire-the curvator-the lens, &c., in operation. Fig. 3 is the curvator. Fig. f 4, is a convex lens. Fig. 5, is the same lens as that in Fig. 4, after the process herein described by which it assumes the required parabolic curvature.

Fig. l. The furnace is constructed of brick as exhibited in Fig. 1, (A) with a top or cover of cast iron (B) which has an aperture (a) which serves as a chimney. C, C, are the projecting ends of the fusing oven which is open at each end and passes through the furnace (b) is the hopper or place for introducing the fuel. (g) lan air door to regulate the draft and remove the ashes. (f) upon the dotted lines shows the position of a common grate.

In Fig. 2, the same letters are applied to the same parts as in the last figure (A) being the edge of the brick furnace, (B) the cast iron cap or cover, (a) the chimney, (Z2) the hopper for supplying fuel-a part of which remains ignited upon the fusing oven and as much as required is removed with a poker through the hopper, and made to'fall on the right and left of the fusingfurnace upon the grate below. the interior of the cast iron fusing oven, with the instrument calledA the curvator (D) and guides (e, e, e, 6,) and handle "(62. ft). Upon t11e 9Q1iYexciirretorjs 50 s hown avles'lf) held in its position by the A, "guides (6,6, c,"e,) and exposed to the heat i viintil it'shall be sufiiciently fused to assume iipnit's'under side, the exact forni of the i ,fmicuvatorf,upon'whih itrests'. M"N i 55 Fig. 3, isa view"of the ciirvator, (D) being a convex plate of platina, of the di- C, C, exhibits ameter required for the lens to be perfected (e, c, e, e, e, 6,) are the guides, also of platina, to hold the lens in its place, or a hoop may be used in their place, (cl, 02) is the handle of the curvator which may be of iron or steel and protected with clay.

(H) in Figsf?J and 4 is the lens before being fused-while (H) in Fig. 5, shows the lens when perfected with the parabolic curvature.

Operation: A double convex lens of the required focal length, is ground in the usual manner one surface being left unfinished or in the state in which it comes from the emery lap. The unfinished surface is placed upon the convex instrument of plasurface of platina is ground to a required convexity and should be of the same diameter as the lens that is to be perfected.) The circumference of the lens is now surrounded with a band von the guides (e, e, &c.) in sections which keep the lens in its place. The coals in the furnace being now ignitedthe curvator (with the lens resting upon it as described) is taken by the handle and placed in the center of the fusing oven (which is of cast iron and of suicient size Oven is kept at a lfl. @v tlierite ef the lrisiflgii.serrated. `theA kcenter of the"`cir`vator the other parts of the lens as they become fused are como f the *convexn lcurvatork and thus, the under or unfinished siclelassuines,thewurye surface will assiinieithat'of a parabola whose4 cii'iiieor' departure" from4 'amcircle will be: ac

concave form, and adouble concavewlens be mf the Vcdurva't'r"iiihileithe ,uppeinorfinished tina called the curvator-(this convex pelledby therirwown vweight to fall onthe cording to the radius`oftheconvexsuifface* i of thelcrvatoi"afnd`lens'The lens havmg only to receive the curvator and lens). The 85 -w# *MM-placed upon its surface the lens under the 2. The construction of the curvator action of hezit will assume a parabolic form with its guides, substantially as herein set on onelsurfaceund a spherical convexity on forth.

the other, and thus any curvature may be'r 3. The process by which any required l5 5 obtained by altering the forni of the curvaparabolic form or curva-ture, may be given 'for or varying' the radius of the two surto the lens as herein set forth in detail.

faces of the lenses. Y T l T W That I claim as my invention and desire HEB RY M PAIB E' to secure by Letters Patent isy lVitnesses: 10 1. The combination of the furnace and JULIUs L. CLARKE,

fusing oven in the manner described. GRENVILLE PARKER. 

